U.S. patent number 10,939,514 [Application Number 16/002,197] was granted by the patent office on 2021-03-02 for electroluminescence display and method for driving the same.
This patent grant is currently assigned to LG DISPLAY CO., LTD.. The grantee listed for this patent is LG Display Co., Ltd.. Invention is credited to Beomjin Kim, Gyungmin Kim.
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United States Patent |
10,939,514 |
Kim , et al. |
March 2, 2021 |
Electroluminescence display and method for driving the same
Abstract
An electroluminescence display and a method for driving the same
are provided to enhance the aging performance of the
electroluminescence display. The electroluminescence display
comprises: a display panel on which a plurality of pixels each
comprising an electroluminescence element; and a power supply part
that outputs a drive voltage for driving the pixels, wherein an
externally applied aging signal is applied to a cathode of the
electroluminescence element to perform aging on the display
panel.
Inventors: |
Kim; Gyungmin (Paju-si,
KR), Kim; Beomjin (Paju-si, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LG Display Co., Ltd. |
Seoul |
N/A |
KR |
|
|
Assignee: |
LG DISPLAY CO., LTD. (Seoul,
KR)
|
Family
ID: |
1000005397531 |
Appl.
No.: |
16/002,197 |
Filed: |
June 7, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20190021151 A1 |
Jan 17, 2019 |
|
Foreign Application Priority Data
|
|
|
|
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Jul 17, 2017 [KR] |
|
|
10-2017-0090363 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05B
33/10 (20130101); G09G 3/3233 (20130101); H01L
51/56 (20130101); G09G 2310/0283 (20130101); G09G
2330/028 (20130101); H01L 2251/562 (20130101); G09G
3/30 (20130101); G09G 2310/08 (20130101); G09G
2330/02 (20130101); G09G 2300/0842 (20130101) |
Current International
Class: |
H05B
33/10 (20060101); H01L 51/56 (20060101); G09G
3/3233 (20160101); G09G 3/30 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
1717130 |
|
Jan 2006 |
|
CN |
|
1768363 |
|
May 2006 |
|
CN |
|
101751858 |
|
Jun 2010 |
|
CN |
|
105070250 |
|
Nov 2015 |
|
CN |
|
105303999 |
|
Feb 2016 |
|
CN |
|
2004/088624 |
|
Oct 2004 |
|
WO |
|
Other References
Office Action dated Dec. 15, 2020 issued in Chinese Patent
Application No. 201810681231.1 w/English Translation (21 pages).
cited by applicant.
|
Primary Examiner: Williams; Joseph L
Assistant Examiner: Stern; Jacob R
Attorney, Agent or Firm: Polsinelli PC
Claims
What is claimed is:
1. An electroluminescence display comprising: a plurality of pixels
each having an electroluminescence element of a display panel, the
electroluminescence element having a cathode and an anode; a power
supply part that outputs a drive voltage for driving the plurality
of pixels; and an aging-only pad and an aging signal line that are
disposed in the cathode electrode and receive an aging signal from
an external power source through the cathode electrode of the
electroluminescence element for aging of the display panel.
2. The electroluminescence display of claim 1, wherein the power
supply part outputs a drive voltage to a drive circuit for driving
the electroluminescence display.
3. The electroluminescence display of claim 2, wherein, during the
aging of the display panel, the drive voltage applied to the
cathode from the power supply part is turned off.
4. The electroluminescence display of claim 1, wherein the power
supply part outputs a high-level voltage VDD, a low-level voltage
COM, and a ground voltage GND for driving the display panel.
5. The electroluminescence display of claim 1, wherein the aging
signal is in a voltage range in which a reverse voltage is applied
to the anode and cathode of the electroluminescence element.
6. The electroluminescence display of claim 1, wherein, during the
aging, the ground voltage GND applied from a high-level voltage
node VDD of the power supply part is applied to the anode of the
electroluminescence element.
7. The electroluminescence display of claim 1, wherein, during the
aging, the ground voltage GND outputted from the power supply part
is applied to a ground node GND of the display panel.
8. An electroluminescence display having a display panel
comprising: an electroluminescence element at the display panel and
having a cathode electrode and an anode electrode; a drive circuit
part that drives the display panel; a power generator that
generates an electrical power; a voltage converter that converts
the generated electrical power to a suppliable voltage and outputs
a drive voltage to the drive circuit part; and an aging-only pad
and an aging signal line that are disposed in the cathode electrode
and receive an aging signal from an external power source through
the cathode electrode of the electroluminescence element for aging
of the display panel.
9. The electroluminescence display of claim 8, wherein the power
generator and the voltage converter constitute a power supply
part.
10. The electroluminescence display of claim 8, wherein the drive
voltage applied to the cathode electrode from the power supply part
is turned off during the aging of the display panel.
11. The electroluminescence display of claim 9, wherein the power
supply part outputs a high-level voltage VDD, a low-level voltage
COM, and a ground voltage GND for driving the display panel.
12. The electroluminescence display of claim 11, wherein the
high-level voltage VDD is in a range of -0.3 V and +5.5 V, the
low-level voltage COM is in a range of -8.0 V and +0.3 V and the
ground voltage GND is 0 V.
13. The electroluminescence display of claim 8, wherein the aging
signal is a reverse voltage that is applied to the anode electrode
and the cathode electrode of the electroluminescence element.
14. The electroluminescence display of claim 8, wherein the ground
voltage GND applied from a high-level voltage node VDD of the
voltage converter is applied to the anode of the
electroluminescence element during the aging of the display
panel.
15. The electroluminescence display of claim 8, wherein, during the
aging, the ground voltage GND outputted from the voltage converter
is applied to a ground node GND of the display panel during the
aging of the display panel.
16. The electroluminescence display of claim 8, further comprising
a switch for turning on and off the aging signal.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of Korean Patent Application
No. 10-2017-0090363 filed on Jul. 17, 2017, which is incorporated
herein by reference in its entirety for all purposes as if fully
set forth herein.
BACKGROUND
Field of the Disclosure
The present disclosure relates to an electroluminescence display
and a method for driving the same.
Description of the Background
Electroluminescence displays can be classified into inorganic
light-emitting displays and organic light-emitting displays
depending on the material of an emission layer. Of these, an
active-matrix organic light emitting display comprises organic
light-emitting diodes (hereinafter, "OLED"), which are typical
light-emitting diodes that emit light themselves, and has
advantages of fast response time, high luminous efficiency, high
brightness, and wide viewing angle.
An OLED of an organic light-emitting display comprises an anode, a
cathode, and an organic compound layer disposed between these
electrodes. The organic compound layer consists of a hole injection
layer (HIL), a hole transport layer (HTL), an emission layer (EML),
an electron transport layer (ETL), and an electron injection layer
(EIL). When a power voltage is applied to the anode and the
cathode, holes passing through the hole transport layer HTL and
electrons passing through the electron transport layer ETL move to
the emission layer EML, forming excitons. As a result, the emission
layer EML generates visible light.
An electroluminescence display comprises a plurality of pixel
circuits formed at the intersections of scan lines, light emission
control lines, and data lines. Each pixel circuit comprises a drive
transistor that operates on a data signal supplied from a data
line, a capacitor for storing voltage between source and gate
electrodes of the drive transistor, and an organic light-emitting
element that emits light by a drive current controlled by a
plurality of transistors and the drive transistor.
By and large, an organic light-emitting display is manufactured
through a manufacturing process for forming a thin-film transistor
(TFT) and a manufacturing process for forming an organic-light
emitting element on the thin-film transistor.
In the manufacturing process for forming an organic light-emitting
element layer, impurities stuck between anode and cathode may cause
short circuits, leading to dark defects.
To solve this, an aging process is carried out to eliminate such
dark defects caused by short-circuits by applying a constant
voltage to the organic light-emitting display. Also, there is a
need for a solution to enhance aging performance in order to
improve product reliability and product yield.
The present disclosure provides an electroluminescence display
capable of enhancing aging performance by eliminating defects
caused by short-circuits between the anode and the cathode of the
electroluminescence display, and a method for driving the same.
SUMMARY
Accordingly, the present disclosure is directed to an
electroluminescence display and a method for driving the same that
substantially obviate one or more of problems due to limitations
and disadvantages of the prior art.
More specifically, the present disclosure provides an
electroluminescence display comprising: a display panel on which a
plurality of pixels each comprising an electroluminescence element;
and a power supply part that outputs a drive voltage for driving
the pixels, wherein an externally applied aging signal is applied
to a cathode of the electroluminescence element to perform aging on
the display panel.
Additional features and advantages of the disclosure will be set
forth in the description which follows and in part will be apparent
from the description, or may be learned by practice of the
invention. Other advantages of the present disclosure will be
realized and attained by the structure particularly pointed out in
the written description and claims hereof as well as the appended
drawings.
In an aspect of the present disclosure, an electroluminescence
display includes a plurality of pixels each having an
electroluminescence element of a display panel, the
electroluminescence element having a cathode and an anode; a power
supply part that outputs a drive voltage for driving the plurality
of pixels; and wherein an externally applied aging signal is
applied to the cathode of the electroluminescence element to
perform aging of the display panel after forming the
electroluminescence element.
In another aspect of the present disclosure, an electroluminescence
display having a display panel includes an electroluminescence
element at the display panel and having a cathode electrode and an
anode electrode; a drive circuit part that drives the display
panel; a power generator that generates an electrical power; a
voltage converter that converts the generated electrical power to a
suppliable voltage and outputs a drive voltage to the drive circuit
part; and an aging-only pad and an aging signal line disposed in
the cathode electrode and receiving an aging signal from an
external power source through the cathode electrode of the
electroluminescence element for aging of the display panel.
The power supply part may output the drive voltage to a drive
circuit for driving the electroluminescence display.
During aging of the display panel, the drive voltage applied to the
cathode from the power supply part may be turned off.
The power supply part may output a high-level voltage VDD,
low-level voltage COM, and ground voltage GND for driving the
display panel.
The aging signal may be in a voltage range in which reverse voltage
is applied to the anode and cathode of the electroluminescence
element.
During the aging, the ground voltage GND applied from a high-level
voltage node VDD of the power supply part is applied to the anode
of the electroluminescence element.
During the aging, the ground voltage GND outputted from the power
supply part is applied to the ground GND of the display panel.
In another aspect, the present disclosure provides a method for
driving an electroluminescence display comprising: a display panel
on which a plurality of pixels each comprising an
electroluminescence element; and a power supply part that outputs a
drive voltage for driving the pixels, the method comprising:
applying, by the power supply part, a high-level voltage VDD and a
ground voltage GND to perform aging on the display panel; and
applying an externally applied aging signal to a cathode of the
electroluminescence element.
An electroluminescence display and a method for driving the same
according to the present disclosure may enhance aging performance
by maximizing the range of swing of cathode voltage and therefore
extending the range of swing of an applicable aging signal.
Furthermore, an electroluminescence display and a method for
driving the same according to the present disclosure may enhance
aging performance by externally generating an aging signal required
for aging and applying it to the cathode.
It is to be understood that both the foregoing general description
and the following detailed description are exemplary and
explanatory and are intended to provide further explanation of the
disclosure as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompany drawings, which are included to provide a further
understanding of the disclosure and are incorporated on and
constitute a part of this application illustrate aspects of the
disclosure and together with the description serve to explain the
principles of the disclosure.
In the drawings:
FIG. 1 is a schematic block diagram of an electroluminescence
display;
FIG. 2 is a circuit diagram showing an example of a pixel circuit
in FIG. 1;
FIG. 3 is a circuit diagram showing an equivalent circuit in the
active area AA of FIG. 1;
FIG. 4 is a view illustrating the principle of aging of an
electroluminescence display;
FIG. 5 is a view showing a power supplying method for an
electroluminescence display according to the present
disclosure;
FIG. 6 is a view of parts of an electroluminescence display
according to an exemplary aspect of the present disclosure; and
FIGS. 7 and 8 are views of parts of an electroluminescence display
illustrating a power supplying method according to an exemplary
aspect of the present disclosure.
DETAILED DESCRIPTION
Reference will now be made in detail aspects of the disclosure,
examples of which are illustrated in the accompanying drawings.
Various aspects and features of the present disclosure and methods
of accomplishing them may be understood more readily by reference
to the following detailed descriptions of exemplary aspects and the
accompanying drawings. The present disclosure may, however, be
embodied in many different forms and should not be construed as
being limited to the exemplary aspects set forth herein. Rather,
these exemplary aspects are provided so that this disclosure will
be thorough and complete and will fully convey the concept of the
present disclosure to those skilled in the art, and the present
disclosure is defined by the appended claims.
The shapes, sizes, proportions, angles, numbers, etc. shown in the
figures to describe the exemplary aspects of the present disclosure
are merely examples and not limited to those shown in the figures.
Like reference numerals denote like elements throughout the
specification. In describing the present disclosure, detailed
descriptions of related well-known technologies will be omitted to
avoid unnecessary obscuring the present disclosure. When the terms
`comprise`, `have`, `consist of` and the like are used, other parts
may be added as long as the term `only` is not used. The singular
forms may be interpreted as the plural forms unless explicitly
stated.
The elements may be interpreted to include an error margin even if
not explicitly stated.
When the position relation between two parts is described using the
terms "on", "over", "under", "next to" and the like, one or more
parts may be positioned between the two parts as long as the term
"immediately" or "directly" is not used.
It will be understood that, although the terms "first", "second",
etc. may be used herein to describe various elements, these
elements are not limited by these terms. These terms are used to
distinguish one element from another element. Thus, a first element
mentioned below could also be termed as a second element without
departing from the technical spirit of the present disclosure.
Like reference numerals denote substantially like elements
throughout the specification.
The following exemplary aspects of the present disclosure may be
coupled or combined with one another either partly or wholly, and
may technically interact or work together in various ways. The
exemplary aspects may be carried out independently or in connection
with one another.
Hereinafter, various exemplary aspects of the present disclosure
will be described in detail with reference to the accompanying
drawings. In the exemplary aspects below, the description of the
electroluminescence display will focus on an organic light-emitting
display comprising organic light-emitting material. However, it
should be noted that the technical idea of the present disclosure
is not limited to organic light-emitting displays but may apply to
inorganic light-emitting displays comprising inorganic
light-emitting material.
An electroluminescence display may be implemented as top-emission
type, bottom-emission type, or dual-emission type depending on the
direction that emitted light exits.
The electroluminescence display may be implemented based on
transistor semiconductor materials such as oxide, low-temperature
polysilicon (LTPS), amorphous silicon (a-Si), or polysilicon
(p-Si).
The electroluminescence display may be implemented in a television,
a navigation device, a video player, a personal computer (PC), a
wearable device (a watch, glasses, etc.), a mobile phone
(smartphone), and so on.
FIG. 1 is a schematic block diagram of an electroluminescence
display.
As shown in FIG. 1, the electroluminescence display comprises a
host system 1000, a timing controller 170, a data driver 130, a
power supply part 140, a gate driver 150, and a display panel
110.
The host system 1000 may comprise a system-on-chip (SoC) having a
scaler incorporated in it, and convert digital video data of an
input image into data signals of a format suitable for display on
the display panel 110. The host system 1000 supplies various timing
signals, along with the data signals, to the timing controller
170.
The timing controller 170 controls the operation timings of the
data driver 130 and the gate driver 150 based on timing signals,
such as a vertical synchronization signal, a horizontal
synchronization signal, a data enable signal, and a main clock,
received from the host system 1000. The timing controller 170
performs image processing (e.g., data compensation, etc.) on the
data signals received from the host system 1000 and supplies them
to the data driver 130.
The data driver 130 operates in response to a data control signal
DDC outputted from the timing controller 170. The data driver 130
converts digital data signals DATA received from the timing
controller 170 into analog data signals.
The data driver 130 converts digital data signals DATA into analog
data signals in response to a gamma voltage from a gamma part
located internally or externally. The data driver 130 supplies data
signals to data lines DL1 to DLn on the display panel 110.
The gate driver 150 operates in response to a gate control signal
GDC outputted from the timing controller 170 and outputs gate
signals (or scan signals) of a gate-high voltage or gate-low
voltage.
The gate driver 150 sequentially outputs gate signals in a forward
or reverse direction and supplies gate signals to gate lines GL1 to
GLm on the display panel 110.
The display panel 110 comprises a display part AA where a plurality
of pixels SP is arranged to display an image and a non-display part
located on the outside of the display part AA. The pixels SP are
connected to the data lines DL1 to DLn and the gate lines GL1 to
GLm. The display panel 110 displays an image in response to gate
signals DATA from the data driver 130.
The power supply part 140 outputs a high-level voltage VDD, a
low-level voltage COM, and a ground voltage GND to drive the
display panel 110. The power supply part 140 may supply the
high-level voltage VDD to the drain of the driving TFT DT of each
pixel SP and the low-level voltage COM to the cathode. An aging
signal R-aging is applied to the display panel 110. The aging
signal R-aging may be supplied to the cathode to perform aging on
the display panel 110.
FIG. 2 is a circuit diagram showing an example of a pixel circuit
in FIG. 1.
A single pixel SP comprises a switching thin-film transistor
(hereinafter, referred to as "TFT") SW connected to a gate line GL
and a data line DL, an organic light-emitting diode EL, and a
driving TFT DT that controls the amount of current flowing through
the organic light-emitting diode EL.
The switching TFT SW turns on in response to a scan signal from the
gate line GL and applies a data voltage from the data line DL to
one electrode of a storage capacitor C.
The driving TFT DT controls the amount of light emitted from the
organic light-emitting diode EL by adjusting the amount of current
supplied to the organic light-emitting diode EL in accordance with
the level of voltage stored in the storage capacitor C.
Each pixel SP is connected to a high-level power supply voltage
source EVDD and a low-level power supply voltage source EVSS to
receive a high-level power supply voltage and a low-level power
supply voltage. A circuit diagram in an active area AA where a
plurality of pixels SP is arranged is as shown in FIG. 3.
FIG. 3 is a circuit diagram showing an equivalent circuit in the
active area AA of FIG. 1.
A plurality of data lines DL and a plurality of gate lines GL
intersect in the active area AA of the display panel 110, and
pixels SP are arranged at the intersections in a matrix form.
Each of the pixels SP included in the display panel 110 is
connected to a high-level power supply voltage source EVDD and a
low-level power supply voltage source EVSS and receives power
supply voltages for driving the pixel SP. GND is connected for
protecting and stabilizing the switching transistor SW and the
driving transistor DR.
The power supply part 140 generates and supplies a high-level
voltage VDD, a low-level voltage COM, and the ground voltage GND
required for driving the display panel 110.
As a consequence, the high-level power VDD generated by the power
supply part 140 is applied to the high-level power supply voltage
source EVDD, i.e., anode of each pixel SP, and the low-level power
COM generated by the power supply part 140 is applied to the
low-level power supply voltage source EVSS, i.e., cathode of each
pixel SP.
With this configuration, the pixels SP of the electroluminescence
display are formed by depositing an anode layer, an organic film
layer, and a cathode layer on a substrate. Through this organic
material deposition process, short-circuits may occur due to
impurities stuck between the anode layer and the cathode layer.
Thus, an aging process is performed on a produced
electroluminescence display before performing a module
configuration.
FIG. 4 is a view illustrating the principle of aging of an
electroluminescence display.
Referring to FIG. 4, the electroluminescence display includes
pixels formed by depositing an anode layer, an organic film layer,
and a cathode layer on a silicon wafer. However, short-circuits may
occur between the anode and the cathode due to impurities or the
like. When the anode and the cathode are short-circuited, a dark
defect can occur in the pixel.
To prevent this, aging is performed to apply an aging signal
between the anode and the cathode, after components for the display
panel are formed on a substrate. The aging signal is a reverse
current signal that is applied between the anode and the cathode.
When a reverse current is applied, impurities and short-circuit
parts of the anode and cathode are separated by the heat produced
by a thermal reaction, thereby clearing the short-circuit
condition.
In the present disclosure, an aging signal is applied directly to
the cathode to sufficiently extend the range of swing of reverse
current used for aging.
FIG. 5 is a view showing a power supplying method for an
electroluminescence display according to the present
disclosure.
The power supply part 140 outputs a high-level voltage VDD, a
low-level voltage COM, and a ground voltage GND for driving the
display panel 110. Typically, the high-level voltage VDD may have a
voltage range of -0.3 V to +5.5 V, and the low-level voltage COM
may have a voltage range of -8.0 V to 0.3 V. The ground voltage GND
is 0 V.
The electrical power outputted from the power supply part 140 is
applied as driving power to each drive circuit CB for driving the
electroluminescence display and also applied as driving power to
the active area AA of the display panel 110.
The high-level voltage VDD outputted from the power supply part 140
is applied to a high-level power supply voltage source EVDD in the
active area AA, and the low-level voltage COM outputted from it is
applied to a low-level power supply voltage source EVSS, i.e.,
cathode, in the active area AA.
When aging is performed on the electroluminescence display, an
aging signal is applied to the low-level power supply voltage
source EVSS, i.e., cathode in the active area AA via a separate
input line, apart from the power input line of the power supply
part 140.
Since the aging signal is an external signal which is applied
regardless of the power supply part 140, the aging signal may have
a voltage level the user wants and be applied directly to the
cathode, without interfering with other circuit components such as
a drive circuit part CB.
FIG. 6 is a view of parts of an electroluminescence display
according to an exemplary aspect of the present disclosure.
Referring to FIG. 6, the display panel 110 and power supply part
140 of the electroluminescence display and the drive circuit part
CB for driving the electroluminescence display may be formed on a
single backplane.
The power supply part 140 may comprise a power generator 142 that
generates electrical power and a voltage converter 144 that
converts the generated electrical power to a suppliable voltage.
The power supply part 140 may generate and output a high-level
voltage VDD, a low-level voltage COM, and a ground voltage GND. The
power supply part 140 may be formed on the backplane or on a
separate backplane.
In normal driving, power supply lines of the power supply part 140
and power supply lines of the circuit components in the drive
circuit part CB and display panel 110 are connected together. In
this regard, the circuit components in the drive circuit part CB
and in the active area AA of the display panel 110 receive the
electrical power outputted from the power supply part 140 as
driving power. The electrical power outputted from the power supply
part 140 is applied as driving power to the drive circuit part CB
and also applied as driving power to the active area AA of the
display panel 110. The high-level voltage VDD outputted from the
power supply part 140 is applied to a high-level power supply
voltage source EVDD in the active area AA, and the low-level
voltage COM outputted from it is applied to a low-level power
supply voltage source EVSS, i.e., cathode in the active area
AA.
The backplane of the electroluminescence display according to the
present disclosure comprises an aging-only pad for applying an
aging signal to a cathode EVSS and a signal line. In this regard,
during aging, an aging signal, instead of the low-level voltage COM
outputted from the power supply part 140, is applied to the cathode
EVSS.
In this way, an externally generated aging signal may be applied to
the cathode EVSS, and therefore there is no limitation on the
voltage of the cathode EVSS and the range of swing of maximum
reverse voltage that can be applied to two ends of the OLED.
Accordingly, an aging signal of the most efficient voltage level
may be generated and applied directly to the cathode EVSS, thereby
maximizing aging performance.
FIGS. 7 and 8 are views of parts of an electroluminescence display
illustrating a power supplying method according to an exemplary
aspect of the present disclosure.
As shown in FIGS. 7 and 8, the timing controller 170, the data
driver 130, the power supply part 140, and the gate driver 150 of
the electroluminescence display, the active area AA of the display
panel, and the drive circuit part CB for driving the
electroluminescence display may be formed on a single
backplane.
The power supply part 140 may comprise a power generator 142 that
generates electrical power and a voltage converter 144 that
converts that converts generated electrical power to a suppliable
voltage. The power supply part 140 may output the generated
electrical power through high-level voltage pads VDD, ground pads
GND, and low-level voltage pads COM.
The drive circuit part CB and the active area AA, which receive the
electrical power generated by the power supply part 140, may
receive driving power through the high-level voltage pads VDD, the
ground pads GND, and the low-level voltage pads COM.
FIG. 7 shows a power input status during normal driving. The power
supply pads VDD, GND, and COM for the power supply part 140 and the
power supply pads VDD, GND, and COM for the drive circuit part CB
and the display panel 110 are connected together.
In this regard, the electrical power outputted from the power
supply part 140 is applied as driving power to the drive circuit
part CB and also applied as driving power to the active area AA of
the display panel 110. The high-level voltage VDD outputted from
the power supply part 140 is applied to a high-level power supply
voltage source EVDD in the active area AA, and the low-level
voltage COM outputted from it is applied to a low-level power
supply voltage source EVSS, i.e., cathode in the active area
AA.
FIG. 8 shows a power input status during aging. The supply of the
low-level voltage through the power supply pads for the power
supply part 140 is selectively turned on or off.
The high-level voltage VDD and the ground voltage GND outputted
from the power supply part 140 are applied as driving power to the
drive circuit part CB and the active area AA.
During aging, the ground voltage GND applied from the high-level
voltage node VDD of the power supply part 140 is applied to the
anode of the electroluminescence element.
The low-level voltage COM outputted from the power supply part 140
is applied to the low-level voltage input pads COM for the drive
circuits CB. However, the voltage input to the low-level power
supply voltage source EVSS in the active area AA is turned off, and
instead, an externally-applied aging signal is applied to the
cathode.
As explained above, the electroluminescence display according to
the present disclosure comprises an aging-only pad for applying an
aging signal to a cathode and signal lines. In this regard, during
aging, an externally generated aging signal, instead of the
low-level voltage outputted from the power supply part, is applied
to the cathode EVSS. Therefore, there is no limitation on the
voltage of the cathode EVSS and the range of swing of maximum
reverse voltage that can be applied to two ends of the OLED.
Accordingly, an aging signal of the most efficient voltage level
may be generated and applied directly to the cathode EVSS, thereby
maximizing aging performance.
Although exemplary aspects of the present disclosure are described
above with reference to the accompanying drawings, it is understood
that those skilled in the art may embody the technical
configuration in other specific forms without changing the
technical spirits and essential features of the present disclosure.
Therefore, it should be understood that the aspects described above
are exemplary and not restrictive in all aspects, and the scope of
the present disclosure is defined by the appended claims rather
than the above specific descriptions. It should be interpreted that
all the changed and modified forms derived from the meaning, scope
and equivalent concepts of the claims are included in the scope of
the present disclosure.
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